This paper discusses mashups, medical mashups for health librarians, specifically. Mashups bring together two or more Web applications to produce a completely new information service. Put another way, a mashup is a hybrid that takes two information sources and merges them to create a third, more useful tool. A good example of a widely used mashup is Google Maps ( http://www. google. com/apis/maps), which combines Google Earth data with telephone directory information to create a useful satellite road map. Although they are part of Web 2.0 and share Web 2.0’s openness, participation, and collaborative aspects, mashups build on a technological base dating back to the earliest days of the Web. By utilizing publicly available and open source code, mashups draw on current awareness tools like Web feeds, really simple syndication (RSS) or Atom, and JavaScript. While still experimental, mashups are worthy of close examination by health librarians interested in exploring new, creative methods of information delivery.